Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: United’s PDX → IAD flights land within a few points of 94% on time whatever the hour.

Nonstops (seasonal or thin)


United	PDX	IAD	5h 02m	94%	0.7%	291	Flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Dulles on time. Total trip = scheduled departure to arrival, layover included (Dulles is 3 h ahead of Portland). Layovers up to 4 hours. Pick a connection for the details.


United Details →	PDX 22:40 → ORD 04:45UA 2094	1h 45m Chicago	ORD 06:30 → IAD 09:24 +1UA 1689	7h 44m	96%	94%
Delta + Unitedtwo ticketsDetails →	PDX 17:24 → SLC 20:19DL 1244	3h 40m Salt Lake City	SLC 23:59 → IAD 06:13 +1UA 726	9h 49m	100%	92%
Alaska + Unitedtwo ticketsDetails →	PDX 10:45 → LAX 13:20AS 695	3h 29m Los Angeles	LAX 16:49 → IAD 00:55 +1UA 1573	11h 10m	99%	91%
United Details →	PDX 23:40 → ORD 05:45UA 1490	2h 55m Chicago	ORD 08:40 → IAD 11:52 +1UA 2277	9h 12m	99%	90%
Alaska + Unitedtwo ticketsDetails →	PDX 08:19 → SEA 09:14AS 2108 · flown by Horizon	3h 46m Seattle	SEA 13:00 → IAD 21:06UA 2131	9h 47m	98%	89%
United Details →	PDX 18:50 → DEN 22:29UA 2334	1h 30m Denver	DEN 23:59 → IAD 05:27 +1UA 1924	7h 37m	95%	89%
Delta + Unitedtwo ticketsDetails →	PDX 06:30 → LAX 09:00DL 2947	3h 43m Los Angeles	LAX 12:43 → IAD 20:48UA 1635	11h 18m	99%	88%
Alaska + Unitedtwo ticketsDetails →	PDX 21:56 → BOS 06:20AS 436	3h 05m Boston	BOS 09:25 → IAD 11:07 +1UA 2098	10h 11m	99%	88%
Tight connection: often missed
United Details →	PDX 13:14 → SFO 15:05UA 2279	1h 29m San Francisco	SFO 16:34 → IAD 00:55 +1UA 1453	8h 41m	67%	58%
United Details →	PDX 14:25 → ORD 20:38UA 2336	1h 02m Chicago	ORD 21:40 → IAD 00:45 +1UA 2766	7h 20m	69%	48%
American Details →	PDX 11:54 → DFW 17:49AA 2287	55m Dallas-Fort Worth	DFW 18:44 → IAD 22:46AA 1132	7h 58m	65%	30%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

SFO · 1h 09m · leaves 05:15 5%

SEA · 53m · leaves 07:19 8%

ATL · 1h 16m · leaves 22:55 15%

Afternoon and evening

IAH · 59m · leaves 13:02 25%

ORD · 1h 02m · leaves 14:25 31%

DFW · 55m · leaves 11:54 35%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.

The table above includes two-ticket connections (marked “two tickets”), held to the 90-minute minimum. One ticket only →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON